Use either this: https://af4a.adj.st/?adjust_t=tj1xyo&adjust_label=BDHTZTB5CWWKSWX6KQG22BZ5SE&adjust_fallback=https%3A%2F%2Fwww.duolingo.com%2Freferred%3Fuser_invite%3DBDHTZTB5CWWKSWX6KQG22BZ5SE%26inviter_id%3D1002970348&adjust_redirect_macos=https%3A%2F%2Fwww.duolingo.com%2Freferred%3Fuser_invite%3DBDHTZTB5CWWKSWX6KQG22BZ5SE%26inviter_id%3D1002970348&adjust_deeplink=duolingo%3A%2F%2Fprofile%3Fuser_id%3D1002970348
Or this: https://invite.duolingo.com/BDHTZTB5CWWKSWX6KQG22BZ5SE